Commit bef4e179 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'bpf-misc' 



Daniel Borkmann says:

====================
Misc BPF improvements

This series adds various misc improvements to BPF, f.e. allowing
skb_load_bytes() helper to be used with filter/reuseport programs
to facilitate programming, test cases for program tag, etc. For
details, please see individual patches.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 18702414 3fadc801

include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -522,6 +522,7 @@ enum bpf_func_id { 
/* BPF_FUNC_l4_csum_replace flags. */

#define BPF_F_PSEUDO_HDR		(1ULL << 4)

#define BPF_F_MARK_MANGLED_0		(1ULL << 5)

#define BPF_F_MARK_ENFORCE		(1ULL << 6)



/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */

#define BPF_F_INGRESS			(1ULL << 0)

kernel/bpf/verifier.c

+45 −19
Original line number Diff line number Diff line
@@ -1566,22 +1566,54 @@ static int evaluate_reg_imm_alu(struct bpf_verifier_env *env, 
	struct bpf_reg_state *dst_reg = &regs[insn->dst_reg];

	struct bpf_reg_state *src_reg = &regs[insn->src_reg];

	u8 opcode = BPF_OP(insn->code);



	/* dst_reg->type == CONST_IMM here, simulate execution of 'add'/'or'

	 * insn. Don't care about overflow or negative values, just add them

	 */

	if (opcode == BPF_ADD && BPF_SRC(insn->code) == BPF_K)

		dst_reg->imm += insn->imm;

	else if (opcode == BPF_ADD && BPF_SRC(insn->code) == BPF_X &&

		 src_reg->type == CONST_IMM)

		dst_reg->imm += src_reg->imm;

	else if (opcode == BPF_OR && BPF_SRC(insn->code) == BPF_K)

		dst_reg->imm |= insn->imm;

	else if (opcode == BPF_OR && BPF_SRC(insn->code) == BPF_X &&

		 src_reg->type == CONST_IMM)

		dst_reg->imm |= src_reg->imm;

	else

	u64 dst_imm = dst_reg->imm;



	/* dst_reg->type == CONST_IMM here. Simulate execution of insns

	 * containing ALU ops. Don't care about overflow or negative

	 * values, just add/sub/... them; registers are in u64.

	 */

	if (opcode == BPF_ADD && BPF_SRC(insn->code) == BPF_K) {

		dst_imm += insn->imm;

	} else if (opcode == BPF_ADD && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm += src_reg->imm;

	} else if (opcode == BPF_SUB && BPF_SRC(insn->code) == BPF_K) {

		dst_imm -= insn->imm;

	} else if (opcode == BPF_SUB && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm -= src_reg->imm;

	} else if (opcode == BPF_MUL && BPF_SRC(insn->code) == BPF_K) {

		dst_imm *= insn->imm;

	} else if (opcode == BPF_MUL && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm *= src_reg->imm;

	} else if (opcode == BPF_OR && BPF_SRC(insn->code) == BPF_K) {

		dst_imm |= insn->imm;

	} else if (opcode == BPF_OR && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm |= src_reg->imm;

	} else if (opcode == BPF_AND && BPF_SRC(insn->code) == BPF_K) {

		dst_imm &= insn->imm;

	} else if (opcode == BPF_AND && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm &= src_reg->imm;

	} else if (opcode == BPF_RSH && BPF_SRC(insn->code) == BPF_K) {

		dst_imm >>= insn->imm;

	} else if (opcode == BPF_RSH && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm >>= src_reg->imm;

	} else if (opcode == BPF_LSH && BPF_SRC(insn->code) == BPF_K) {

		dst_imm <<= insn->imm;

	} else if (opcode == BPF_LSH && BPF_SRC(insn->code) == BPF_X &&

		   src_reg->type == CONST_IMM) {

		dst_imm <<= src_reg->imm;

	} else {

		mark_reg_unknown_value(regs, insn->dst_reg);

		goto out;

	}



	dst_reg->imm = dst_imm;

out:

	return 0;

}
@@ -2225,14 +2257,8 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) 
		return err;



	if (insn->src_reg == 0) {

		/* generic move 64-bit immediate into a register,

		 * only analyzer needs to collect the ld_imm value.

		 */

		u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;



		if (!env->analyzer_ops)

			return 0;



		regs[insn->dst_reg].type = CONST_IMM;

		regs[insn->dst_reg].imm = imm;

		return 0;

net/core/filter.c

+32 −31
Original line number Diff line number Diff line
@@ -1522,10 +1522,11 @@ BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset, 
{

	bool is_pseudo = flags & BPF_F_PSEUDO_HDR;

	bool is_mmzero = flags & BPF_F_MARK_MANGLED_0;

	bool do_mforce = flags & BPF_F_MARK_ENFORCE;

	__sum16 *ptr;



	if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_PSEUDO_HDR |

			       BPF_F_HDR_FIELD_MASK)))

	if (unlikely(flags & ~(BPF_F_MARK_MANGLED_0 | BPF_F_MARK_ENFORCE |

			       BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK)))

		return -EINVAL;

	if (unlikely(offset > 0xffff || offset & 1))

		return -EFAULT;
@@ -1533,7 +1534,7 @@ BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset, 
		return -EFAULT;



	ptr = (__sum16 *)(skb->data + offset);

	if (is_mmzero && !*ptr)

	if (is_mmzero && !do_mforce && !*ptr)

		return 0;



	switch (flags & BPF_F_HDR_FIELD_MASK) {
@@ -2598,7 +2599,7 @@ static const struct bpf_func_proto bpf_xdp_event_output_proto = { 
};



static const struct bpf_func_proto *

sk_filter_func_proto(enum bpf_func_id func_id)

bpf_base_func_proto(enum bpf_func_id func_id)

{

	switch (func_id) {

	case BPF_FUNC_map_lookup_elem:
@@ -2625,6 +2626,17 @@ sk_filter_func_proto(enum bpf_func_id func_id) 
	}

}



static const struct bpf_func_proto *

sk_filter_func_proto(enum bpf_func_id func_id)

{

	switch (func_id) {

	case BPF_FUNC_skb_load_bytes:

		return &bpf_skb_load_bytes_proto;

	default:

		return bpf_base_func_proto(func_id);

	}

}



static const struct bpf_func_proto *

tc_cls_act_func_proto(enum bpf_func_id func_id)

{
@@ -2680,7 +2692,7 @@ tc_cls_act_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_skb_under_cgroup:

		return &bpf_skb_under_cgroup_proto;

	default:

		return sk_filter_func_proto(func_id);

		return bpf_base_func_proto(func_id);

	}

}
@@ -2695,7 +2707,7 @@ xdp_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_xdp_adjust_head:

		return &bpf_xdp_adjust_head_proto;

	default:

		return sk_filter_func_proto(func_id);

		return bpf_base_func_proto(func_id);

	}

}
@@ -2706,7 +2718,7 @@ cg_skb_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_skb_load_bytes:

		return &bpf_skb_load_bytes_proto;

	default:

		return sk_filter_func_proto(func_id);

		return bpf_base_func_proto(func_id);

	}

}
@@ -2733,7 +2745,7 @@ lwt_inout_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_skb_under_cgroup:

		return &bpf_skb_under_cgroup_proto;

	default:

		return sk_filter_func_proto(func_id);

		return bpf_base_func_proto(func_id);

	}

}
@@ -2784,19 +2796,8 @@ static bool __is_valid_access(int off, int size) 
	switch (off) {

	case offsetof(struct __sk_buff, cb[0]) ...

	     offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:

		if (size == sizeof(__u16) &&

		    off > offsetof(struct __sk_buff, cb[4]) + sizeof(__u16))

			return false;

		if (size == sizeof(__u32) &&

		    off > offsetof(struct __sk_buff, cb[4]))

			return false;

		if (size == sizeof(__u64) &&

		    off > offsetof(struct __sk_buff, cb[2]))

			return false;

		if (size != sizeof(__u8)  &&

		    size != sizeof(__u16) &&

		    size != sizeof(__u32) &&

		    size != sizeof(__u64))

		if (off + size >

		    offsetof(struct __sk_buff, cb[4]) + sizeof(__u32))

			return false;

		break;

	default:
@@ -2994,7 +2995,7 @@ void bpf_warn_invalid_xdp_action(u32 act) 
}

EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);



static u32 sk_filter_convert_ctx_access(enum bpf_access_type type,

static u32 bpf_convert_ctx_access(enum bpf_access_type type,

				  const struct bpf_insn *si,

				  struct bpf_insn *insn_buf,

				  struct bpf_prog *prog)
@@ -3221,7 +3222,7 @@ static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type, 
				      offsetof(struct net_device, ifindex));

		break;

	default:

		return sk_filter_convert_ctx_access(type, si, insn_buf, prog);

		return bpf_convert_ctx_access(type, si, insn_buf, prog);

	}



	return insn - insn_buf;
@@ -3253,7 +3254,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, 
static const struct bpf_verifier_ops sk_filter_ops = {

	.get_func_proto		= sk_filter_func_proto,

	.is_valid_access	= sk_filter_is_valid_access,

	.convert_ctx_access	= sk_filter_convert_ctx_access,

	.convert_ctx_access	= bpf_convert_ctx_access,

};



static const struct bpf_verifier_ops tc_cls_act_ops = {
@@ -3272,24 +3273,24 @@ static const struct bpf_verifier_ops xdp_ops = { 
static const struct bpf_verifier_ops cg_skb_ops = {

	.get_func_proto		= cg_skb_func_proto,

	.is_valid_access	= sk_filter_is_valid_access,

	.convert_ctx_access	= sk_filter_convert_ctx_access,

	.convert_ctx_access	= bpf_convert_ctx_access,

};



static const struct bpf_verifier_ops lwt_inout_ops = {

	.get_func_proto		= lwt_inout_func_proto,

	.is_valid_access	= lwt_is_valid_access,

	.convert_ctx_access	= sk_filter_convert_ctx_access,

	.convert_ctx_access	= bpf_convert_ctx_access,

};



static const struct bpf_verifier_ops lwt_xmit_ops = {

	.get_func_proto		= lwt_xmit_func_proto,

	.is_valid_access	= lwt_is_valid_access,

	.convert_ctx_access	= sk_filter_convert_ctx_access,

	.convert_ctx_access	= bpf_convert_ctx_access,

	.gen_prologue		= tc_cls_act_prologue,

};



static const struct bpf_verifier_ops cg_sock_ops = {

	.get_func_proto		= sk_filter_func_proto,

	.get_func_proto		= bpf_base_func_proto,

	.is_valid_access	= sock_filter_is_valid_access,

	.convert_ctx_access	= sock_filter_convert_ctx_access,

};

tools/testing/selftests/bpf/Makefile

+2 −2
Original line number Diff line number Diff line 
CFLAGS += -Wall -O2 -I../../../../usr/include



test_objs = test_verifier test_maps test_lru_map test_lpm_map

test_objs = test_verifier test_tag test_maps test_lru_map test_lpm_map



TEST_PROGS := test_verifier test_maps test_lru_map test_lpm_map test_kmod.sh

TEST_PROGS := $(test_objs) test_kmod.sh

TEST_FILES := $(test_objs)



all: $(test_objs)

tools/testing/selftests/bpf/test_tag.c

0 → 100644
+202 −0
Original line number Diff line number Diff line 
#include <stdio.h>

#include <stdlib.h>

#include <ctype.h>

#include <time.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <sched.h>

#include <limits.h>

#include <assert.h>



#include <sys/socket.h>

#include <sys/resource.h>



#include <linux/filter.h>

#include <linux/bpf.h>

#include <linux/if_alg.h>



#include "../../../include/linux/filter.h"



#include "bpf_sys.h"



static struct bpf_insn prog[BPF_MAXINSNS];



static void bpf_gen_imm_prog(unsigned int insns, int fd_map)

{

	int i;



	srand(time(NULL));

	for (i = 0; i < insns; i++)

		prog[i] = BPF_ALU64_IMM(BPF_MOV, i % BPF_REG_10, rand());

	prog[i - 1] = BPF_EXIT_INSN();

}



static void bpf_gen_map_prog(unsigned int insns, int fd_map)

{

	int i, j = 0;



	for (i = 0; i + 1 < insns; i += 2) {

		struct bpf_insn tmp[] = {

			BPF_LD_MAP_FD(j++ % BPF_REG_10, fd_map)

		};



		memcpy(&prog[i], tmp, sizeof(tmp));

	}

	if (insns % 2 == 0)

		prog[insns - 2] = BPF_ALU64_IMM(BPF_MOV, i % BPF_REG_10, 42);

	prog[insns - 1] = BPF_EXIT_INSN();

}



static int bpf_try_load_prog(int insns, int fd_map,

			     void (*bpf_filler)(unsigned int insns,

						int fd_map))

{

	int fd_prog;



	bpf_filler(insns, fd_map);

	fd_prog = bpf_prog_load(BPF_PROG_TYPE_SCHED_CLS, prog, insns *

				sizeof(struct bpf_insn), "", NULL, 0);

	assert(fd_prog > 0);

	if (fd_map > 0)

		bpf_filler(insns, 0);

	return fd_prog;

}



static int __hex2bin(char ch)

{

	if ((ch >= '0') && (ch <= '9'))

		return ch - '0';

	ch = tolower(ch);

	if ((ch >= 'a') && (ch <= 'f'))

		return ch - 'a' + 10;

	return -1;

}



static int hex2bin(uint8_t *dst, const char *src, size_t count)

{

	while (count--) {

		int hi = __hex2bin(*src++);

		int lo = __hex2bin(*src++);



		if ((hi < 0) || (lo < 0))

			return -1;

		*dst++ = (hi << 4) | lo;

	}

	return 0;

}



static void tag_from_fdinfo(int fd_prog, uint8_t *tag, uint32_t len)

{

	const int prefix_len = sizeof("prog_tag:\t") - 1;

	char buff[256];

	int ret = -1;

	FILE *fp;



	snprintf(buff, sizeof(buff), "/proc/%d/fdinfo/%d", getpid(),

		 fd_prog);

	fp = fopen(buff, "r");

	assert(fp);



	while (fgets(buff, sizeof(buff), fp)) {

		if (strncmp(buff, "prog_tag:\t", len))

			continue;

		ret = hex2bin(tag, buff + prefix_len, len);

		break;

	}



	fclose(fp);

	assert(!ret);

}



static void tag_from_alg(int insns, uint8_t *tag, uint32_t len)

{

	static const struct sockaddr_alg alg = {

		.salg_family	= AF_ALG,

		.salg_type	= "hash",

		.salg_name	= "sha1",

	};

	int fd_base, fd_alg, ret;

	ssize_t size;



	fd_base = socket(AF_ALG, SOCK_SEQPACKET, 0);

	assert(fd_base > 0);



	ret = bind(fd_base, (struct sockaddr *)&alg, sizeof(alg));

	assert(!ret);



	fd_alg = accept(fd_base, NULL, 0);

	assert(fd_alg > 0);



	insns *= sizeof(struct bpf_insn);

	size = write(fd_alg, prog, insns);

	assert(size == insns);



	size = read(fd_alg, tag, len);

	assert(size == len);



	close(fd_alg);

	close(fd_base);

}



static void tag_dump(const char *prefix, uint8_t *tag, uint32_t len)

{

	int i;



	printf("%s", prefix);

	for (i = 0; i < len; i++)

		printf("%02x", tag[i]);

	printf("\n");

}



static void tag_exit_report(int insns, int fd_map, uint8_t *ftag,

			    uint8_t *atag, uint32_t len)

{

	printf("Program tag mismatch for %d insns%s!\n", insns,

	       fd_map < 0 ? "" : " with map");



	tag_dump("  fdinfo result: ", ftag, len);

	tag_dump("  af_alg result: ", atag, len);

	exit(1);

}



static void do_test(uint32_t *tests, int start_insns, int fd_map,

		    void (*bpf_filler)(unsigned int insns, int fd))

{

	int i, fd_prog;



	for (i = start_insns; i <= BPF_MAXINSNS; i++) {

		uint8_t ftag[8], atag[sizeof(ftag)];



		fd_prog = bpf_try_load_prog(i, fd_map, bpf_filler);

		tag_from_fdinfo(fd_prog, ftag, sizeof(ftag));

		tag_from_alg(i, atag, sizeof(atag));

		if (memcmp(ftag, atag, sizeof(ftag)))

			tag_exit_report(i, fd_map, ftag, atag, sizeof(ftag));



		close(fd_prog);

		sched_yield();

		(*tests)++;

	}

}



int main(void)

{

	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };

	uint32_t tests = 0;

	int i, fd_map;



	setrlimit(RLIMIT_MEMLOCK, &rinf);

	fd_map = bpf_map_create(BPF_MAP_TYPE_HASH, sizeof(int),

				sizeof(int), 1, BPF_F_NO_PREALLOC);

	assert(fd_map > 0);



	for (i = 0; i < 5; i++) {

		do_test(&tests, 2, -1,     bpf_gen_imm_prog);

		do_test(&tests, 3, fd_map, bpf_gen_map_prog);

	}



	printf("test_tag: OK (%u tests)\n", tests);

	close(fd_map);

	return 0;

}

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